In various settlement terminals, e.g., a card settlement terminal which carries out the settlement of a transaction by a credit card, tampering can occur to change the terminal to output recorded information used for a settlement, such as the credit card information read from a credit card. For this reason, various events serving as signs of changes to the terminal, such as forcibly opening a housing, are monitored, and in a case in which such an event occurs, the terminal is prevented from operating normally thereafter by deleting a program or the data necessary for the normal operation thereof.
However, if the configuration of the tamper detection technology is known, it is possible to avoid detection of tampering relatively easily. Further, in a case in which a treatment such as deleting a program, or the taking of data occurs, if the deleted program or data is not restored, the normal operation of the terminal cannot be restored.